Last month we talked about heart disease in dogs, and this month we are discussing heart disease in cats and how this can present differently than in dogs. Heart disease is common in cats, affecting up to 1 in 8 cats according to multiple studies.
Many cats will have a normal life expectancy with no cardiac-related issues, while there are some cats that may have severe and life-threatening consequences. It can be very difficult to identify which category a cat may fall into, especially without advanced diagnostics.
Generally, heart disease in cats is divided into congenital (present at birth) and acquired. Congenital disease can be hereditary/genetic or be a single mutation present in only one kitten in the litter. Acquired occurs as the result of damage to the heart during the cat’s life. There can be a genetic predisposition to acquired heart disease, or it can develop due to diet, weight, and/or other diseases. Certain breeds (Maine Coons, Siamese, Persians, British & American Shorthairs) can be predisposed to heart disease. The most common heart disease in cats is adult-onset hypertrophic cardiomyopathy, which is the thickening of the heart muscle.
Many cats will not display any signs of cardiac disease until it is advanced. Cats rarely cough if they have heart disease, and while exercise intolerance will occur, it is not always recognizable in a cat. The most common signs that cats will display are decreased appetite, weight loss, increased respiratory rate and effort, collapse, and hind limb paralysis. Acute collapse and death can sometimes be the only sign and can occur suddenly. Cats can be masters at masking their ailments.
Many people have heard of their pets having a heart murmur. A murmur is an abnormal heart sound typically caused by turbulent blood flow. In dogs, the detection of a heart murmur can be the first sign that there is cardiac disease. In cats, a murmur is not always heard – and, to make it more complicated, a murmur doesn’t always reflect heart disease. A large study revealed that 40% of cats had murmurs, but only about 30% of those cats had actual heart disease. On the other hand, many cats with heart disease did not have a murmur, but rather presented with respiratory signs (trouble breathing). Therefore, it is important to consider additional testing if a heart murmur is detected or if the veterinarian is suspicious of heart disease. If a murmur is heard when the cat is young, this could indicate a congenital malformation.
If heart disease is suspected, radiographs, echocardiograms, ECGs, and blood work are all part of determining the cause and significance. Similar to dogs, a veterinary cardiologist is often necessary to understand and treat the problem.
Treatment of cardiac disease in cats will depend on the cause. Some congenital issues require surgery, while others are managed with diet and medications. Common medications will include ACE inhibitors, beta blockers, diuretics and blood thinners. Diets supplemented with omega 3 fatty acids and taurine are very important for cats. Even in healthy cats, a diet poor in taurine can lead to life threatening heart disease.
The prognosis for heart disease in cats is varied. Some cats can live a full life without any complications, while some can be affected as young as 3 months old and may have a very poor prognosis. The best approach is to make sure your pet is evaluated at least yearly or sooner if you notice any of the above signs mentioned. Sometimes, their heart disease is not treatable, but we can use the information to understand and perhaps even avoid breeding certain genetics, if indicated.